Means for controlling the operation of die casting apparatus automatically and in timed relation



G. NYsELlUs 2,896,279 MEANS FOR coNTRoLLrNG THE: OPERATION oF um CASTING July 28, 1959 APPARATUS AUTOMATICALLY AND IN TIMED RELATION Filed July 6, 1956 4 Sheets-Sheet 1 Lev I l C wm .LULV

July 28, l959 G. NYsELlus 2,896,279

MEANS FOR CONTROLLING THE OPERATION 0F DIE CASTING APPARATUS AUTOMATICALLY AND IN TIMED RELATION Filed July 6, 1956 4 Smeets-Sheet 2 NvENToR A 620741/ /VYnH/L/s BY y/Mms'ld ATTORNEYS July 28, 1959 G. NYsELlus 2,896,279

MEANS FOR CONTROLLING THE OPERATION OF DIE CASTING 'APPARATUS AUTOMATICALLY AND IN TIMED RELATION Filed Juli.r 6, 1956 4 Sheets-Sheet 3 j BY July 28, 1959 G. NYsELlUs 2,896,279

MEANS FOR coNTRoLLTNG THE OPERATION oF DIE CASTING APPARATUS AuToMATTcALLY AND 1N TIMED RELATION Filed July e, 195e 4 sheets-sheet 4 RNEYS Unite MEANS FOR CONTRLLING THE OPERATIO 'DIE CASTING APPARATUS AUTOMATICALLY AND IN TIMED RELATION This application relates to die casting apparatus and more particularly to means for controlling the operations of such apparatus automatically and in timed-relation.

An object of the invention is to provide means for rendering more automatic the operation of die casting apparatus of the kind disclosed herein.

Another object of the invention is to provide improved control means which is compact and may readily be added to previously manufactured die casting machines.

Another object of the invention is to provide a detachable sub-assembly facilitating exhausting air from the mold of apparatus of the kind described herein in timed relation to feeding molded metal into the mold, which may be readily transferred from one machine to another.

Another object of the invention is to provide apparatus by the use of which castings of improved quality may be obtained.

Other objects will be apparent from reading the folflowng description and claims,

The invention will best be understood if the following "description is read in connection with the drawings in rchine with my improved control means attached to it.

Figure 2 is a diagrammatic view of Ielectrical circuits,

comprising the said control means.

Figure 3 is a top plan view of part of the said control Figure 4 is a diagrammatic side elevation of Fig. 3

:showing the turntable and air and vacuum control valves.

Figure 5 is a side elevation of mold plate 12 and at- '.tached control member 50.

Figure 6 is a detail View showing the position of com- Yplementary member 50 and 51 when mold members 12 fand 16 are closed together, and

Figure 7 is a view similar to Figure l but 'showing a modication of the control means.

Apart from the control means the die casting machine described herein is of known kind. It comprises va stationary frame member 10 to which a mold plate 12 may be demountably attached, as by bolts b, and a movable frame member 14 which carries the mold plate 16 which coacts with plate 12 to provide a mold closure. The movable frame member 14 is connected to toggle means 18 which is actuated by movements of piston rod and the piston 22 which is responsive to fluid pressure exerted on it in one direction or the other within cylinder 24. A source of fluid pressure is connected Vthrough two-position 4-way valve 25 and conduits 26 and 28 leading to said cylinder on opposite sides respectively of piston 22 therein, the position of valve 25 determining the direction of movement of the piston.

Projecting from the outer face of member 10 and communicating through a bore 3) in member 10 with which it is aligned is a tubular receptacle 32 for molten metal, which is cut away at the top for convenience in charging the receptacle by means of-a ladle. Aligned -with the States Patent axis of the receptacle 32 and bore 30 is a reciprocable plunger 34 having an enlarged head portion 36 suitable for pushing a molten metal charge from said receptacle 32 through the bore 30 in member 10 and through the bore 38 in mold plate 12 which is aligned with bore 30 and communicates between it and the mold cavity.

Plunger 34 is actuated by movements of piston rod 40 and the piston 42 which is responsive to fluid pressure exerted on it in one direction or the other within cylinder 43. A source of fluid pressure is connected through two# position, 4-wayA valve 44 and conduits 46 and 48 leading to said cylinder on opposite sides respectively of piston 42 therein, the position of `valve 44 determining the direction of movement of the piston. Valve 44 is opened twice to provide two forward movements of piston 40, the first for advancing the plunger 34 into the bore 30 in member 1t) and close said bore behind it, and the second to charge the metal into the mold after the mold has been evacuated.

The interior surface of mold plate 12 is provided with the small grooves or gates 49 and 49a. .Connected to mold member 12, preferably detachable for transfer from one machine to another, is a member 50 which has the surface groove or gate 52 .aligned with groove ,49. Connected to mold member 16 is a member 51 which has a surface adapted to tit tightly against the grooved surface of member 50. Blocks 50 and 51 are detachably connected to mold ,members 12 and 16 respectively by Z-shaped clamps 50a and 51a which extend into transverse slots X in said blocks respectively. When mold plate 16 has been closed against mold plate 12 member 51 covers the semicircular groove or gate 52 and converts it into a conduit through which air may be exhausted from the mold.

Communicating with passage 52 is a bore 54 in block 50 in which is a reciprocable member 56 biased away frompassage 52 by spring 58 but which when forced into passage 52 closes it preventing molten metal from advancing into said passage beyond this point. As shown the outer face of member 56 is inclined, and riding lon said face is a projectable member 60 which moves member 56 into passage 52 against the action of spring 58 as it advances over said inclined face of member' 56. Member 60 is controlled by compressed air supplied from a suitable source 61 through valve 62 and conduit 64 and 64' when said valve is opened. Inserted in the outer end of passage 52 is a ilexible conduit 66 which is connected through filter F, conduit 67, air valve 73 andv conduit 67 to vacuum pump 68 which is actuated by motor 70 connected in an electric circuit which may be completed by closing of switch 72. Conduit 67 is connected by conduit 67" to vacuum tank V. Valves 6'2 and 73 are positioned adjacent the turntable 74.

Turntable 74 may be rotated by any suitable means. As shown herein it is actuated electrically by motor 76 through the gear reduction unit 78. Connected in circuit with said motor is a push button switch 81, by the operation of which rotation of the turntable may be started, and a limit switch 82 positionedclose to said turntable.

Carried by the turntable are a number of cam mem.- bers. As shown the cams 84 on top of the turntable serve to lguide a cam follower 86 on one end of arm 88, the other end of which is connected to said valve 44. The initial and final or return movements of valve 44 are actuated by movements of said arm 88 `derived from the conta-ct of cams 84 on said cam follower 86. As will be noted the second movement of valve 44 depends on air cylinder C actuated as will be described by an electric circuit including switch 89. In Figure 1 the moving turntable 74 is a rst source of power actingY on arm 88 which is a first/link to valve 44, and the cylinder C is a second source of power acting on valve 44 through linkage which includes the plunger 93 of cylinder C and link 95. As will be noted from Figure 3 cams 84 cause said cam follower to move both outwardly and inwardly of a circular path concentric with the axis of said turntable, which for convenience is referred to herein as the neutral line. When rotation of the turntable is started cams 84 move said cam follower out and back from the neutral line through a gradual curve a and this movement of cam follower 86 and arm 88 turns valve 44 to supply fluid briey through conduit 46 causing piston 42 to move in a direction which advances plunger 34 only sufficiently to push a charge of molten metal from receptacle 32 into bore 30 and to close said bore behind the molten metal therein, after which valve 44 is returned to neutral position and the plunger again is stationary until air has been exhausted from the mold. Exhausting of the mold is accomplished by cam 90, shown on the periphery of the turntable, contacting valve 73. The evacuating step is terminated by cam 92 on the turntable contacting valve 62 thereby causing member 60 to be projected against member 56 thus advancing member 56 and closing the passage 52 and preventing molten metal from being drawn through passage 52 upon being pushed into the mold by plunger 34 which is now advanced for this purpose.

Plunger 34 is advanced sharply to charge the mold by cams 84 moving cam follower 86 outwardly from its neutral line in the straight line b which causes arm 88 to turn valve 44 to supply fluid pressure to the cylinder 43 on the side of piston 42 which causes plunger 34 to move toward said mold. This action of arm 88 is caused by force of compressed air from cylinder C the valve D of which is actuated by an electric circuit including switch 89 which is closed by contact with projection member 91 on turntable 74. The plunger 93 of the compressed air cylinder C is attached to the stem of valve 44 by link 95.

The machine is now opened and plunger 34 is now able to complete its inward or Working stroke and in so doing helps to dislodge the metal casting from the front half of the mold. During the portion of a revolution of the turntable,` from b to c, Where carn follower 86 is moved in sharply by said cams 84, cam follower 86 has been held at the same distance beyond its neutral line. Its movement along the portion of its path indicated as c brings the follower inwardly across said neutral line and this movement of the follower and arm 88 turns valve 44 to supply fluid pressure to the other side of the piston in cylinder 43 thereby reversing the stroke of the plunger causing it to retract.

The machine may be both closed and opened automatically by cam means on said turntable. As a safety precautionV however, the machine is closed by the hand lever 94 acting through link 96 and arm 97 which is connected to valve 25, and is opened automatically and plunger 34 is retracted by the projection 98 on the turntable striking the extension 97a of arm 97 thus both restoring hand lever 94 to its initial position and turning valve 25 to supply fluid pressure to the side of the piston 22 in cylinder 24 to retract the toggle means 18 and thus open the mold by moving mold plate 16 away from mold plate 14.

A projection 100 carried by the turntable now strikes limit switch 82 thus opening the circuit of motor 76 and stopping rotation of the turntable. This provides time for the next mold charge to be ladled into the receptacle 32 before starting the next cycle of operation by closing said switch 81, but it will be understood that if the receptacle is filled automatically projection 100 may be omitted and the turntable permitted to revolve continuously to control a number of cycles of operation without a stop between cycles.

In Fig. 7 a modification of the control means is shown. Valve 25 is employed for closing the machine at the beginning of an operating cycle and for opening it near the end of the cycle. In place of valve 44 for operating metal charging plunger 34 two valves 44a and 44b are employed. Valve 44a, through conduits 109 and 111 to opposite sides of piston 42 in Water cyclinder 43 controls the first forward movement of the piston 42 and metal feeding plunger 34, which is the first operating step after the machine is closed, and the return of metal feeding plunger 34, which is the last operating step in each cycle. Valve 44b controls the second forward movement of metal feeding plunger 34.

The machine is closed by power supplied by air cylinder 1 the piston rod l-aof which is connected to valve 25 on one side of its center and rotates it to permit fluid under pressure to ow into cylinder 24 through conduit 26 thereby actuating piston 22, in water cylinder 24, to close the machine. Air cylinder 1 is controlled by an electric circuit which I prefer to close manually by means of the push button switch 101.

Also connected to Water valve 25 is the air cylinder 4 the piston rod 4a of which is connected to valve 25 j on the other side of its center from its connection to the piston rod l-a of cylinder 1 and which serves to open the machine as will be described.

Air cylinders 2 and 5 are connected to valve 44a, on opposite sides of its center, by piston rods 2a and 5a respectively, and air cylinder 3 is connected to valve 44b by piston rod 3a. Cylinder 2 is a first source of power used for the first stage of the charging stroke. Cylinder 3 isa second source of power used for the second stage of the charging stroke.

On turntable 74 are the six cams 102, 104, 106, 108, 110 and 112, and mounted on the circular support 114 which surrounds turntable 74' are the cam followers 102:1 and 104a, 106a, 110a and 112a which are of known When a cam'follower moves off its cam the wheel w and its support arm drop down thus opening the electric circuit or closing the air valve as the case may be.

v The circuit controlled by cam follower 102a is connected to cylinder 2 which is linked to water valve 44a and actuates the metal feeding plunger to move through the first part of its stroke, valve 44a being returned to neutral when the cam follower moves olf its cam.

The cam follower 104a controls an air valve Fig. 7 in the negative pressure conduit 66 shown in Fig. 1.

The cam follower 106a controls an air valve Fig. 7 in the compressed air conduit 64 shown in Fig. 1.

The cam follower 108a controls the electric circuit leading to cylinder 3 connected to water valve 44b and actuates the metal feeding plunger to move through the second portion of its stroke, valve 44b being returned to neutral, i.e. closed position when this cam follower moves off its cam.

The cam follower 110a is connected to air cylinder 4 which turns valve 25 to open the machine.

The cam follower 112a is connected to air cylinder 5 which turns valve 44a to return the metal charging plunger 34 to its starting position. When follower 112a moves off its cam valve 44a is returned to neutral position, ending an operating cycle of the machine.

It will be noted that cam 104 overlaps cam 106; that 106 overlaps 108; and that 108 overlaps 110. Cam 104 serves to start reduction of pressure in the mold immediately after the first movement of the metal feeding plunger 34, and continues the reduced pressure until the vacuum line 49 is closed by the plug 54, through means actuated by cam 106. Cam 106 has enough length to keep the vacuum line plugged until after the casting is formed. Cam 106 thus overlaps the cam 108 which actuates the means by which valve 44b is turned to canse the metal feeding plunger 34 to be advanced through the second part of its stroke.

The air cylinders employed are of known kind in which a piston is actuated by a solenoid connected in the circuits respectively.

Valves 25, 44a and 44b are shown respectively connected to a main pressure line 116 through branch conduits 118, 120 and 122. If desired a known means for reducing the pressure of uid delivered to said valves may be employed. Such a means is indicated by the numeral 134, inserted in branch conduit 120.

There has thus lbeen provided an improvement in apparatus for automatic control of die casting machines in which the various objects set forth above are successfully achieved with many thoroughly practical advantages. It will be understood that the description and drawings are illustrative and not to be interpreted in a limiting sense.

What I claim is:

1. In a die casting machine having a mold and a reciprocable plunger to push molten metal into the mold, means for actuating the plunger in two charging steps and a return step, including, a iluid cylinder and piston means therein connected to said plunger, a source of fluid under pressure, a conduit interconnecting said source of fluid pressure and said fluid cylinder on opposite sides of the piston therein, a four-way valve in said conduit, two operating arms connected to said valve, a first source of power, and means connecting it to one of said operating arms, a second source of power and means connecting it to the other of said operating arms, said rst named connecting means including a turntable, cam means thereon, a cam follower and link means connecting said cam follower -to one of said operating arms for rotating said valve mechanically upon actuation of said cam follower by said cam means, said second named connecting means including an air cylinder, link means connecting said air cylinder to said second operating arm, and an electrical circuit for controlling said air cylinder, said circuit including a switch and means carried by said turntable for opening and closing said switch in timed relation to the actuation of said cam follower by said cam means.

2. The apparatus claimed in claim 1 including a vacuum line connected to said mold, means for exerting negative pressure on said vacuum line including air valve means, separate means for closing said vacuum line in timed relation to feeding molten metal into said mold, including a compressed air conduit, a source of compressed air, and valve means for controlling the supply of compressed air from said source into said conduit, means for opening the mold, and means on said turntable for actuating each of said aforementioned means in timed sequence.

References Cited in the le of this patent UNITED STATES PATENTS 1,724,332 Will et al Aug. 13, 1929 1,974,822 Lannert Sept. 25, 1934 1,989,812 Lester Feb. 5, 1935 2,216,059 Vontobel et al Sept. 24, 1940 2,243,835 Brunner et al June 3, 1941 2,293,087 Tann Aug. 18, 1942 2,581,550 Misfeldt Jan. 8, 1952 2,668,985 Babbitt Feb. 16, 1954 2,774,122 Hodler Dec. 18, 1956 

